DAVY 169 



and the manner in which this food is supplied and prepared for their 

 nourishment. . . . Nothing is more wanting in agriculture than experi- 

 ments, in which all the circumstances are minutely and scientifically 

 detailed. 



The attractions of society and his early death (he was 

 only fifty) stopped his work on agricultural chemistry ; 

 and it was not until 1840, eleven years after Davy's 

 death, that Liebig published his ever famous work on the 

 same subject. 



Kumford and Davy proved that heat was not matter, 

 as had been previously supposed, but a form of energy 

 the vis viva of the molecules. But the crowning dis- 

 coveries of Davy were those necessitating the use of the 

 electric battery. To Davy, " the electrolysis of every 

 chemical compound was a new application of the great 

 law established by Newton : ' to every action there is 

 an equal and opposite reaction." By means of the elec- 

 tric battery he decomposed bodies which were generally 

 regarded as elements or simple bodies. 



On 19th October 1807 Davy isolated the metals potas- 

 sium and sodium by electrolyzing potash and soda. In 

 the former case, potassium and hydrogen were evolved 

 at the negative pole, and oxygen at the positive pole of 

 the battery. When Davy first saw the metallic globules 

 of potassium, "he could not contain his joy he actually 

 bounded about the room in ecstatic delight ; and some 

 little time was required for him to compose himself 

 sufficiently to continue the experiment." This was the 



